Gameboy - 2 Player Link Cable advice please

Have bought ds1 and ds2 a link cable. We have followed instructions but none of the games we have that are 2 player will come up on both consoles. I know that it says sometimes you will need a game in each console but I was hoping that we wouldn't have to go down this route. I am also now unsure if the cable actually works. Can anyone tell me which games are able to be played with the link cable when there is only one game cartridge in one gameboy. That way I can find a friend who may have the game so we can borrow and test our cable.

Hi the only ones ds has played with with his friend are ones that they both had so both had the game in each gameboy.
I will ask himn in the morning if he knows how to do it without games in both or if in fact you can and get back to you.!!